Comparisons were made of beetles collected at various times after deposition from the dung of cattle treated with fenvalerate-impregnated ear tags for horn flies,Haematobia irritans(L.), and untreated cattle. The study was conducted on cattle pastured in two different range types, sandhills prairie and a combination of mixed and sandsage prairie. The horn fly larvae present in dung from treated cattle were significantly fewer (P<0.05) than in dung from untreated cattle. However, consideration of beetles by a coefficient of community index and species evenness index indicated that lack of horn fly eggs and larvae did not create much difference in either numbers of species or of individuals within a species. There was a greater difference in beetles between the two rangeland types than between the treatments within each rangeland type.